1. Field of the Invention
This invention relates to filing systems and more particularly to visible indexing systems and elements thereof for the compact storage and high speed retrieval of data in the form of printed material, microfilm, microfiche and the like.
2. Discussion of the Prior Art
Various types of visibly indexed filing systems for the storage of printed material in the form of file cards and for the storage of information in the form of microfilm jackets and microfiche are known in the prior art. The basic objects of these systems typically involve the competing requirements of high density filing and rapid retrieval of information from the system. To achieve rapid retrieval of information, it is necessary to be able to expeditiously obtain full visibility of the title area of any individual file element within the system. This goal can, of course, be achieved by designing a system wherein the title area of each card in the system is at all times visible. An example of this type of system is the commonly found visible card file system in which the file cards are hinged in flat trays with from three-sixteenth inch to one-fourth inch of each individual file cards exposed by overlapping the elements within the trays. This type of system has the obvious disadvantage that only a rather limited number of file cards can be filed in a given linear space. For example, the typical hinged type visible file requires approximately 23 linear inches to file 69 standard file cards of the type here being considered. By comparison, my invention as described herein permits the filing of over 350 file cards in a tray having a length of 16 inches.
In the visible filing of the card form of microfilm or microfiche, which is one of the applications of the invention described herein, approximately one-half inch is required for display of the title area. One type of visible microfiche file utilizes paper panels in which offset pockets are formed to receive the microfiche film card. Visible display of 15 microfiche cards would therefore require 71/2 inches of space for title display. Visible microfiche panels of this type are usually 81/2.times.11 inches and are filed in notebooks. Alternately, they may be side-mounted around a central column to create a "tower."
Other visible microfiche files known in the prior art employ individual clear plastic jackets which are contained in multiple-ring binders. Here again, the visibility of each title is achieved by the offset filing of each fiche.
In each of the above-mentioned visible index files for card or microfilm forms, valuable linear file space must be set aside for title area display, and the total linear dimension of all titles must be searched with each reference to the file. Further, sequential or categoric indexing is extremely difficult and viewing is limited to one panel at a time.
One of the most successful vertical filing type of prior art systems is described in U.S. letters Pat. No. 3,301,263 issued to Arthur T. Spees, the present inventor.
Another type of prior art vertical filing system of which I am aware is a magnetic type system which is presently commercially available. In this magnetic type index filing system, thin steel wafers or shims are sandwiched between two pieces of paper which are sealed together to form the index cards. These cards, with the metal insert on both sides, react with permanent magnets located on each side of a file tray in such a manner as to cause individual cards to separate or fan apart wherever cards converge at opposing angles. The magnetic system achieves the compactness of vertical filing, but true or full visibility of individual cards is limited due to the lack of control over the separation of cards. In the reference area, where the "V" is created, for example, as many as 25 cards may be separated or fanned within a 31/2 inch span. The result is that only the very top edge of each card can actually be viewed; and since one-quarter inch is required for a one-line title and one-half inch for microfiche titles, the visible feature of the magnetic file is limited.
As will become apparent from the description of the invention which follows, the disadvantages of the previously described prior art systems are overcome due to the highly novel and unique design of the file elements and file receptacle of my invention.
The system of my invention not only allows extremely high density filing of fully protected file elements but, at the same time permits rapid information-retrieval. Rapid retrieval is made possible by a unique mechanical interaction among the file elements in the form of backing cards or divider cards (and hereinafter in this paragraph referred to as "backing cards") within the file, whereby the individual backing cards can be caused to separate or fan apart at their top portions when the backing cards converge at their bottom edges from opposing angles under slight pressure. This mechanical interaction, which will be described in detail hereinafter, basically involves providing an added thickness or fulcrum laterally across each backing card and below center vertically, usually near the bottom edge, which serves as a pivot axis around which the adjacent backing card in the file can rotate when the backing cards are held compactly together or slightly compressed at their bottom edges. To control this pivotal action the backing cards are provided with receptacle engaging means for positioning them in the file in such a manner that they are forced to pivot around the fulcrum when their lower edges are urged together. These engaging means permit the backing cards to move freely longitudinally, but eliminates relative vertical movement.
Prior art patents which represent the closest art known to applicant and which clearly demonstrate the novelty of applicant's invention as described and claimed herein are the following:
______________________________________ Patentee No. Issue Date ______________________________________ Brower 769,855 Sept. 13, 1904 Kouba 1,073,248 Sept. 16, 1913 Gebser 1,730,069 Oct. 1, 1929 Vance 1,801,943 Apr. 21, 1931 Strassel 1,835,678 Dec. 8, 1931 Herz 1,931,224 Oct. 17, 1933 Copeland 2,169,318 Aug. 15, 1939 Wurzburg 2,171,105 Aug. 29, 1939 McDermott 2,284,586 May 26, 1942 Jonas 2,329,201 Sept. 14, 1943 Short 2,371,713 Mar. 20, 1945 ______________________________________